1. Field of the Invention
This invention relates to the prevention of accidental hollow-bore needle-stick injuries whereby health car workers can become infected with blood-borne pathogens, including human immunodeficiency virus (HIV), hepatitis B virus (HBV) and hepatitis C virus (HCV), during and after withdrawal of hollow-bore steel IV access needles having rigid round or soft rectangular hubs permanently attached to trailing tubing.
2. Description of Prior Art
To prevent needle-stick injuries to health care workers, puncture-resistant cylinders which slide over syringes to extend beyond the tip of an injection needle and,then, lock by mechanical means are now produced by Becton-Dickson and Sherwood Medical Corporations. Similar open-ended shields which slide over the trailing tubing in infusion assemblies and blood collecting devices have been described, but are not in common use. However, such shields are crucial in preventing needle-stick injuries to health care workers, because phlebotomy needles are customarily inserted into veins and, therefore, customarily hold blood in their bores during and after withdrawal.
The use of tethers as parts of needle shields have been described by Slaughter (U.S. Pat. No. 4,781,697--Nov. 1, 1988), Dombrowski et al (U.S. Pat. No. 4,790,828--Dec. 13, 1988), Corey (U.S. Pat. No. 4,955,866--Sep. 11, 1990), and Simon (U.S. Pat. No. 5,051,109--Sep. 24, 1991). None of these describe a tether which uses an IV access site in a patient for an anchor.
In U.S. Pat. No. 4,932,946, issued Jun. 12, 1990, Shields described a tab 11 on the leading end of a slit elastomeric robe containing a cylindrical needle shield for safely exposing and recapping the tip of a hollow-bore steel needle attached to a standard syringe. This invention is pertinent, but not applicable because syringes lack trailing tubing.
In U.S. Pat. No. 5,061,250, issued Oct. 29, 1991, Shields described a tether with a tab finger-held over a vein in order to pull a slit elastomeric tube containing a puncture-resistant cone over a needle during withdrawal. This invention, incorporating a tether 16 with an attached tab 17 and a trailing cone 13 is pertinent to the the instant invention, but not directly applicable because effective use depends on the inclusion of a slit elastomeric tube attachable to the hub of an IV infusion needle with trailing silastic robing.
In U.S. Pat. No. 5,197,956, issued Mar. 30, 1993, Brizuela described a slotted puncture-resistant cylinder with a beveled trailing ring 7 which can slide over Wailing tubing attached to a serum bag to safely entrap a leading cannula by means of a protrusion 12 of trailing tubing over its attachment to the cannula hub 10. He described a cap 8 with a tether 9 for closing the leading end of said cylinder after the cannula is withdrawn. He did not describe a leading tether or tab for stabilizing this cylinder over a venipuncture site.
In U.S. Pat. No. 4,943,283, issued Jul. 24, 1990, Hogan described two hollow cylinders 30,40 concentrically added during assembly to prevent needle-stick injuries from phlebotomy sets having hollow-bore steel needles on each end of segmented silastic tubing. In a second preferred embodiment, the tubing permanently attached to the IV access needle is supplied with such a cylinder. Hogan does not include a leading tether, tab or a trailing cone for wedge-impacting the trailing end of a round or rectangular needle hub. Instead, the device depends on adding a wedge-like detent 43 on the leading end of the trailing tubing 14 to prevent forward motion of the needle hub after its trailing portions of least diameter have been retracted through a series of radial slits 53 in a cupped trailing end of the cylinder 40.
In U.S. Pat. No. 5,112,311, issued May 12, 1992, Utterberg and Sheehan described a puncture-resistant cylinder 1 with a leading tether 122, a tab 124 and paired slots 1c which slide together over the hub 3 of a winged infusion assembly to safely enclose the infusion needle 5 after use. They described use of the tether and tab for anchoring the cylinder with respect to an IV access site during needle withdrawal. (See FIG. 14). However, withdrawal, forward and backward excursion of the tethered puncture-resistant and slotted cylinder is limited to the length of wing attachment to the needle hub, especially when said assembly is supplied, as claimed, as a surrounding attachment to a the hub of a winged infusion needle assembly. This invention applies only to winged infusion assemblies, and is structurally inapplicable to IV infusion needles having round or rectangular trailing hubs of small diameter lacking "butterfly" wings.
In U.S. Pat. No. 5,085,639, issued Feb. 4, 1992, Ryan teaches use of a stepped hollow cylinder within the body of a winged infusion assembly for safely trapping a retracted infusion needle having a hub with shoulders matching the steps. He did not teach the use of a leading tether for anchoring the winged body during retraction of the leading hollow-bore steel needle, or the use of a simple cone to wedge-impact the trailing end of the hub which holds and stabilizes the needle during IV insertion and retraction.
In U.S. Pat. No. 4,935,011, issued Jun. 19, 1990, Hogan taught use of a flat envelope into which an IV access needle attached to a winged infusion can be safely withdrawn, part of said envelope comprising a compression flap adapted to overlie the venipuncture site while the needle is being withdrawn from a patient's vein. This patent does not include the use of cylindrical or conical shields for needle protection, and is applicable only to winged or "butterfly" infusion assemblies attached to Wailing tubing.
In U.S. Pat. No. 5,176,657, issued Jan. 5, 1993, Shields described a hollow conical shield used to first contain a fluid-filled cartridge and, used later, a to wedge impact the leading end of a rigid dental syringe into which this cartridge is breech-inserted, so that the leading tip of hollow-bore steel needle is always protected before, between uses and after use for giving dental anesthesia. This patent is cogent, because it teaches the use of a hollow cone to wedge impact the leading end of a rigid syringe into a confined puncture-resistant space wherein a leading hollow-bore steel needle can be held and manipulated safely. However, this patent does not embody, include or necessitate the use of a tether for safe usage.
The use of matching hollow cylinders or cones with solid cones of decreasing diameter to create wedge impactions is common practice with respect to the leading ends of needle hubs inserted into needle shields or sheaths supplied with disposable hollow-bore steel needles. However, the use of a hollow cone to wedge impact the trailing end of a round or rectangular needle hub of an IV access needle attached to trailing tubing is novel in the prevention of needle-stick injuries. The attachment of leading tethers to such hollow conical shields is novel, except as claimed in Shields' U.S. Pat. No. 4,932,946, along with slanting of the leading large apertures and constriction of trailing apertures, as described below.